急等！！！！！！ 转一个 sql 为 oracle

Question

if exists(select * from Product_Category where Commonality=@Commonality and Pid=0 and Title=@Title)
select Id from Product_Category where Commonality=@Commonality and Pid=0 and Title=@Title 
else 
   begin 
    insert Product_Category(Pid,Title,Commonality, OrderSort) 
    select 0, @Title, @Commonality,(select isnull(max(OrderSort),0)+1 from Product_Category) as OrderSort
    select @@identity
   end转换为oracle  尽量的简单·

Answer 1

if   exists(select   *   from   Product_Category   where   Commonality=@Commonality   and   Pid=0   and   Title=@Title)
select   Id   from   Product_Category   where   Commonality=@Commonality   and   Pid=0   and   Title=@Title  
else  
      begin  
        insert   Product_Category(Pid,Title,Commonality,   OrderSort)  
        select   0,   @Title,   @Commonality,(select   isnull(max(OrderSort),0)+1   from   Product_Category)   as   OrderSort
        select   @@identity
      end

Answer 2

declare
v_cnt int;
v_seq int;
begin
v_cnt := 0;select   count(*) into v_cnt
from   Product_Category   where   Commonality=&Commonality   and   Pid=0   and   Title=&Title;if v_cnt>0 then
insert   Product_Category(Pid,Title,Commonality,   OrderSort)  
select   0,   &Title,  & Commonality,
(select   nvl(max(OrderSort),0)+1   from   Product_Category)   as   OrderSort from dual; 
-- select   序列名.currval into v_seq  from dual;  -- @@identity这句不知道有什么用处
end if;
end

Answer 3

select   @@identity
我知道这个是取SQL SERVER 自增列的ID啊，自增列在ORACLE用序列表示的？
select   序列名.currval into v_seq  from dual;

Answer 4

[code=SQL]declare
v_Commonality  Product_Category.Commonality%type;
v_Title   Product_Category.Title%type;
num number;
v_id Product_Category.id%type;
begin
select count(*) into num from Product_Category   where   Commonality=v_Commonality  and   Pid=0   and   Title=v_Title;
if num>0 then
select id into v_id from Product_Category  where Commonality=v_Commonality  and   Pid=0   and   Title=v_Title;
else
insert Product_Category(Pid,Title,Commonality, OrderSort) 
select 0,v_Title,v_Commonality,(select nvl(max(OrderSort),0)+1 from Product_Category) OrderSort from dual;
---select   @@identity  这个自增干什么;
end;